Positive pole piece of cylindrical battery and cylindrical battery

Abstract

The utility model discloses a positive pole piece of a cylindrical battery and the cylindrical battery, the positive pole piece of the cylindrical battery comprises a current collector, a first positive pole material layer and a second positive pole material layer, the first positive pole material layer is arranged on at least partial area of at least one surface of the current collector; the second positive electrode material layer is arranged on at least part of the surface of one side, far away from the current collector, of the first positive electrode material layer; the second positive electrode material layer comprises a plurality of coating areas, and one gap blank area is arranged between every two adjacent coating areas. According to the positive pole piece of the cylindrical battery, the first positive pole material layer is arranged on the current collector, and the second positive pole material comprising the plurality of coating areas and the gap blank areas is arranged on the second positive pole material layer, so that gas generated by SEI formed by a positive pole and a negative pole during formation can be eliminated in time; the wettability of the electrolyte and the safety and the electrochemical performance of the cylindrical battery are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of lithium-ion batteries, and in particular to a positive electrode sheet of a cylindrical battery and a cylindrical battery. Background Art

[0002] At present, the positive electrode plates of most cylindrical batteries are continuously coated strip structures, which can meet the basic application of lithium iron phosphate system. However, as the energy density demand of lithium-ion batteries for power batteries becomes higher and higher, the low energy density of lithium iron phosphate system cannot be further improved, and it is difficult to fully meet the energy density demand of power batteries. Recently, cylindrical batteries of ternary system have attracted more and more attention due to their high energy density, high manufacturing efficiency and low cost.

[0003] However, the inventors found that due to the characteristics of high compaction density and high voltage, the cylindrical battery of the ternary system has serious gas production, is difficult to penetrate the electrolyte, and has low safety. The conventional strip structure is extremely difficult to improve the above difficulties in the application of the ternary positive electrode system in the cylinder, resulting in a poor cycle life of the ternary system cylindrical battery.

[0004] Therefore, there is an urgent need to develop a cylindrical battery that can overcome the gas generation problem and improve the electrolyte infiltration degree and battery safety. Summary of the invention

[0005] In view of this, one purpose of the present application is to propose a positive electrode plate for a cylindrical battery. By arranging a first positive electrode material layer on the current collector and arranging a second positive electrode material including a plurality of coating areas and gap blank areas on the second positive electrode material layer, the gas generated by the formation of SEI by the positive and negative electrodes during formation can be promptly removed, thereby improving the wettability of the electrolyte and the safety and electrochemical performance of the cylindrical battery, especially improving its cycle life.

[0006] Another object of the present application is to provide a cylindrical battery.

[0007] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a positive electrode sheet of a cylindrical battery, comprising:

[0008] current collector;

[0009] A first positive electrode material layer, wherein the first positive electrode material layer is provided on at least a portion of at least one surface of the current collector;

[0010] The second positive electrode material layer is arranged on at least a portion of the surface of the first positive electrode material layer away from the current collector; the second positive electrode material layer includes a plurality of coating areas, and a gap blank area is provided between two adjacent coating areas.

[0011] In some embodiments, a plurality of the coating zones are arranged in parallel.

[0012] In some embodiments, the widths of the plurality of gap blank areas are equal.

[0013] In some embodiments, the widths of the plurality of gap blank areas are not equal.

[0014] In some embodiments, the width of the gap blank area is 0.5-10 mm.

[0015] In some embodiments, a surface of the coating region away from the current collector is arranged parallel to the current collector.

[0016] In some embodiments, the positive electrode active material of the first positive electrode material layer is different from the positive electrode active material of the coating region.

[0017] In some embodiments, the positive electrode active material of the first positive electrode material layer includes a molecular formula of Li x MO2 material, lithium iron phosphate or lithium iron manganese phosphate, wherein x is 1-1.5, and M is selected from at least one of Ni, Mn, Co or Al.

[0018] Preferably, the positive electrode active material of the first positive electrode material layer is LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.9 Co 0.05 Mn 0.05 O2, lithium iron phosphate or lithium iron manganese phosphate.

[0019] In some embodiments, the positive electrode active material in the coating area is lithium iron phosphate or lithium manganese iron phosphate.

[0020] In some embodiments, the thickness of the first positive electrode material layer is 40-120 μm.

[0021] In some embodiments, the coating region has a thickness of 2-30 μm.

[0022] In order to achieve the above-mentioned purpose, a second embodiment of the present application proposes a cylindrical battery, including the positive electrode plate of the cylindrical battery of the embodiment of the present application.

[0023] The positive electrode sheet of the cylindrical battery in the embodiment of the present application can at least bring the following beneficial effects:

[0024] 1. A second positive electrode material layer containing a coating area and a gap blank area arranged at intervals is arranged in the positive electrode plate, wherein the gap blank area can timely remove the gas generated by SEI formed by the positive and negative electrodes during formation, thereby preventing the gas from remaining in the battery cell system and blocking the transmission of lithium ions, resulting in lithium deposition in the battery; in addition, the gap blank area provides more channels for the electrolyte, making it easier for it to enter the battery cell; the infiltration degree of the electrolyte is improved, and at the same time, the blank area has better liquid retention capacity, stores more electrolyte, and improves the cycle life of the battery cell.

[0025] 2. The first positive electrode material layer is arranged between the second positive electrode material layer having the coating area and the blank area arranged at intervals and the current collector, which can further improve the energy density and safety of the cylindrical battery.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0028] Figure 1 1 is a top view of a positive electrode sheet of a cylindrical battery shown in an exemplary embodiment of the present application, wherein a represents the winding direction of the battery cell.

[0029] Figure 2 yes Figure 1 The cross-sectional view of the AA plane, where a represents the winding direction of the battery cell.

[0030] Reference numerals:

[0031] 1-current collector; 2-first positive electrode material layer; 3-second positive electrode material layer; 301-coating area; 302-gap blank area. DETAILED DESCRIPTION

[0032] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application.

[0033] The positive electrode sheet of the cylindrical battery in the embodiment of the present application is described below with reference to the accompanying drawings.

[0034] Figure 1 1 is a top view of a positive electrode sheet of a cylindrical battery shown in an exemplary embodiment of the present application.

[0035] like Figure 1 and Figure 2As shown, the positive electrode sheet of the cylindrical battery in the embodiment of the present application includes a current collector 1, a first positive electrode material layer 2 and a second positive electrode material layer 3.

[0036] The first positive electrode material layer 2 is disposed on at least a portion of at least one surface of the current collector 1 .

[0037] It can be understood that the first positive electrode material layer 2 can be provided on one or more surfaces of the current collector, and can be provided on a partial area or the entire area of ​​the corresponding surface (ie, the first positive electrode material 2 covers the corresponding surface of the current collector).

[0038] The second positive electrode material layer 3 is disposed on at least a portion of the surface of the first positive electrode material layer 2 on a side away from the current collector 1 .

[0039] It can be understood that the second positive electrode material layer 3 is disposed on a portion of the surface of the first positive electrode material layer 2 away from the current collector 1 .

[0040] The second positive electrode material layer 3 includes a plurality of coating regions 301 , and a gap blank region 302 is provided between two adjacent coating regions 301 .

[0041] It can be understood that in the embodiments of the present application, the coating area is the area covered by the second positive electrode material on the surface of the first positive electrode material layer, and the gap blank area is the area on the surface of the first positive electrode material layer not covered by the second positive electrode material and located between two adjacent coating areas.

[0042] As an optional example, the number of coating areas is greater than 3 and less than 100.

[0043] It should be noted that, in the embodiments of the present application, the widths of the coating areas may be equal or unequal.

[0044] In some embodiments, two adjacent coating areas are arranged at a certain angle, which can be an acute angle or an obtuse angle.

[0045] In some embodiments, several coating areas 301 are arranged in parallel. In the embodiments of the present application, several coating areas 301 are arranged in parallel, which makes the coating process more convenient and the processing efficiency higher.

[0046] In some embodiments, the surface of the coating area 301 away from the current collector 1 is arranged parallel to the current collector 1. In this way, the free electrolyte can quickly infiltrate into the inside of the electrode through the gap area, accelerating the infiltration speed of the electrolyte; at the same time, the gas generated in the formation stage of the first positive electrode material layer can be discharged in time and discharged from the battery body through negative pressure formation.

[0047] In some embodiments, the widths of the plurality of gap blanking regions 302 are equal.

[0048] In some other embodiments, the widths of the plurality of gap blank areas 302 are not equal.

[0049] In the embodiments of the present application, the gap blank area can promptly remove the gas generated by the SEI formed by the positive and negative electrodes during formation, thereby preventing the gas from remaining in the battery cell system and blocking the transmission of lithium ions, leading to lithium precipitation in the battery; in addition, the gap blank area provides more channels for the electrolyte, making it easier for it to enter the battery cell, thereby improving the wetting degree of the electrolyte. At the same time, the blank area has better liquid retention capacity, stores more electrolyte, and improves the cycle life of the battery cell.

[0050] In some embodiments, the width of the gap blank area 302 is 0.5-10 mm, including but not limited to 0.5 mm, 2 mm, 4 mm, 6 mm, 8 mm or 10 mm.

[0051] In the embodiment of the present application, the positive electrode active material of the first positive electrode material layer 2 may be the same as or different from the positive electrode active material of the coating area 301. If they are the same, the coating method is more diverse and the coating production efficiency is higher.

[0052] In some embodiments, the positive electrode active material of the first positive electrode material layer 2 includes a molecular formula of Li x MO2 material, wherein x is 1-1.5, including but not limited to 1, 1.1, 1.2, 1.3, 1.4 or 1.5, etc.; M is selected from at least one of Ni, Mn, Co or Al.

[0053] As a non-limiting example, when the positive electrode active material molecular formula of the first positive electrode material layer 2 includes the above Li x In the case of MO2, the positive electrode active material of the first positive electrode material layer 2 includes but is not limited to LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.9 Co 0.05 Mn 0.05 At least one of O2, etc.

[0054] In some other embodiments, the positive electrode active material of the first positive electrode material layer 2 further includes at least one of lithium iron phosphate (LiFePO 4 ) or lithium iron manganese phosphate.

[0055] In some embodiments, the molecular formula of lithium manganese iron phosphate is LiMn y Fe 1-y PO4, wherein 0.1≤y≤0.9, including but not limited to 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.

[0056] As an optional example, the positive electrode active material of the first positive electrode material layer 2 includes but is not limited to LiNi 1 / 3Co 1 / 3 Mn 1 / 3 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.9 Co 0.05 Mn 0.05 At least one of O2, lithium iron phosphate (LiFePO4) or lithium iron manganese phosphate.

[0057] In some embodiments, the positive active material of the coating area 301 includes but is not limited to at least one of lithium iron phosphate (LiFePO4) or lithium iron manganese phosphate, etc. The molecular formula of lithium iron manganese phosphate is the same as above and will not be repeated here.

[0058] It should be noted that the positive electrode active material of the first positive electrode material layer of the present application is selected from the above molecular formula Li x MO2 material can improve the battery energy density; the positive electrode active material in the coating area of ​​the second positive electrode material layer is selected from lithium iron phosphate or lithium iron manganese phosphate, etc., which can improve the gas production problem under positive high pressure and increase battery safety; the active material of the first positive electrode material layer and the positive electrode active material in the coating area of ​​the second positive electrode material layer are used in combination to balance the energy density and safety.

[0059] Therefore, as an optional example, the positive electrode active material of the first positive electrode material layer 2 is the above-mentioned molecular formula Li x At least one of the materials of MO2; the positive electrode active material of the coating area 301 of the second positive electrode material layer 3 is at least one of lithium iron phosphate or lithium manganese iron phosphate.

[0060] In some embodiments, the material of the first positive electrode material layer and the material of the coating area may further include a positive electrode conductive agent, a positive electrode binder, etc. The positive electrode conductive agent includes but is not limited to at least one of conductive carbon black (Super-P), graphite, acetylene black, graphene, carbon fiber, carbon nanotubes, etc.; the positive electrode binder includes but is not limited to at least one of polyvinylidene fluoride (PVDF), sodium alginate, sodium carboxymethyl cellulose, and polyacrylic acid, etc.

[0061] As an optional example, in the material of the first positive electrode material layer, the mass ratio of the positive electrode active material, the positive electrode conductor and the positive electrode binder is 97.6:1.3:1.1.

[0062] In some embodiments, the thickness of the first positive electrode material layer 2 is 40-120 μm, including but not limited to 40 μm, 60 μm, μm, 80 μm, 100 μm or 120 μm, etc. The thickness of the first positive electrode material layer within the above range can improve the battery energy density and rate performance; less than 40 μm, the energy density will be reduced; greater than 120 μm, the rate performance will deteriorate.

[0063] In some embodiments, the thickness of the coating area 301 is 2-30 μm, including but not limited to 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm or 30 μm, etc. When the thickness of the coating area is within the above range, the rate performance can be improved to a limited extent, while increasing the electrolyte infiltration speed, ensuring the electrolyte retention rate, and timely discharging the gas generated in the formation stage; when it is less than 2 μm, it is difficult to improve the electrolyte infiltration speed; when it is greater than 30 μm, the positive electrode energy density may be sacrificed.

[0064] In some embodiments, the current collector may be selected to include aluminum or any other suitable conductive metal foil (such as solid or mesh or covered foil) known to those skilled in the art, a metal grid or screen, or a porous metal. In some variations, the surface of the current collector may include a metal foil that has been surface treated (e.g., carbon coated and / or etched).

[0065] The positive electrode plate of the cylindrical battery of the embodiment of the present application is provided with a second positive electrode material layer containing a coating area and a gap blank area at intervals in the positive electrode plate, wherein the gap blank area can timely remove the gas generated by the formation of SEI by the positive and negative electrodes during formation, and avoid the gas remaining in the battery system, blocking the transmission of lithium ions, causing the battery to precipitate lithium and then produce internal short circuits and cause safety problems; at the same time, the gap blank area provides more channels for the electrolyte, making it easier for it to enter the battery cell; improves the degree of electrolyte infiltration, and at the same time, the blank area has better liquid retention capacity, stores more electrolyte, and improves the cycle life of the battery cell. In addition, the first positive electrode material layer is provided between the second positive electrode material layer containing the coating area and the gap blank area at intervals and the current collector, which can further improve the energy density and safety of the cylindrical battery.

[0066] The cylindrical battery of the embodiment of the present application includes the positive electrode plate of the cylindrical battery of the embodiment of the present application.

[0067] Certain features of the present technology are further illustrated in the following non-limiting examples.

[0068] Example

[0069] (Cylindrical battery positive electrode)

[0070] like Figure 1 As shown, the cylindrical battery positive electrode sheet of this embodiment includes a current collector 1, a first positive electrode material layer 2 and a second positive electrode material layer 3. The first positive electrode material layer 2 is arranged on two opposite surfaces of the current collector 1. The second positive electrode material layer 3 is arranged on the surface of the first positive electrode material layer 2 away from the current collector 1. The second positive electrode material layer 3 includes 5 coating areas 301, and a gap blank area 302 is provided between two adjacent coating areas 301. The width of each coating area is 120mm ( Figure 2 y1=y2=120mm), all coating areas 301 are arranged in parallel, the surface of the coating area 301 away from the current collector 1 is arranged in parallel with the current collector 1, and the width of all gap blank areas 302 is 0.5mm ( Figure 2 (x1=x2=x3=0.5 mm). The material of the first positive electrode material layer 2 is composed of the following components in parts by weight: LiNi 0.8 Co 0.1 Mn 0.1 O2 97.6 parts, conductive carbon black (Super-P) 1.3 parts, PVDF 1.1 parts. The material of the coating area 301 is composed of the following components in weight: lithium iron phosphate (LiFePO4) 96.5 parts, conductive carbon black (Super-P) 2 parts, PVDF 1.5 parts. The thickness h1 of the first positive electrode material layer 2 is 100μm, and the thickness h2 of the coating area 301 is 10μm. The current collector is a 12μm Al foil substrate.

[0071] (Preparation of positive electrode sheet for cylindrical battery)

[0072] The positive electrode active material - LiNi 0.8 Co 0.1 Mn 0.1 O2, conductive carbon black Super-P, and binder PVDF are mixed in a N-methylpyrrolidone (NMP) solvent system at a weight ratio of 97.6:1.3:1.1, and are fully stirred by a vacuum mixer to obtain a first positive electrode material slurry; the first positive electrode material slurry is intermittently coated on two opposite surfaces of a 12μm Al foil substrate, and then dried to form a first positive electrode material layer 1; then 96.5 parts by weight of lithium iron phosphate LiFePO4, 2 parts by weight of conductive carbon black Super-P, and 1.5 parts by weight of binder PVDF are mixed in an N-methylpyrrolidone (NMP) solvent system, and are fully stirred by a vacuum mixer to obtain a coating area positive electrode slurry; the coating area positive electrode slurry is intermittently coated on two surfaces of the first positive electrode material layer 1 away from the current collector, and then dried to form a second positive electrode material layer 2. Then, drying, cold pressing, striping, and cutting are performed in sequence to obtain a positive electrode sheet.

[0073] (Preparation of negative electrode sheet)

[0074] The negative electrode active material-graphite, the conductive agent-sp (also known as Super-P), the binder-styrene-butadiene rubber and the thickener-sodium carboxymethyl cellulose are dissolved in deionized water at a weight ratio of 96.5:1:1.2:1.3, and the negative electrode slurry is obtained after being fully stirred and mixed. The negative electrode slurry is extrusion coated on the surface of the negative electrode current collector 6μm Cu foil, and then dried, cold pressed and cut in sequence to obtain the negative electrode sheet.

[0075] (Preparation of Electrolyte)

[0076] Ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) are mixed in a volume ratio of 3:3:4 to obtain an organic solvent, and then fully dried LiPF6 is dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0077] (Preparation of isolation film)

[0078] The isolation membrane substrate is 8 μm thick polyethylene (PE), and a 2 μm alumina ceramic layer is coated on both opposite sides of the isolation membrane substrate. Finally, 2.5 mg of binder polyvinylidene fluoride (PVDF) is coated on both sides of the ceramic layer and dried.

[0079] (Preparation of cylindrical batteries)

[0080] The positive electrode sheet, isolation film and negative electrode sheet are stacked in order, so that the isolation film is placed between the positive electrode sheet and the negative electrode sheet to play an isolating role, and then wound to obtain a bare battery cell; the qualified bare battery cell is loaded into a cylindrical shell, and then the tabs are welded to the top cover current collecting plate, and finally the electrolyte is injected after drying, and after standing, forming, aging, sealing nail welding and other processes, a lithium-ion cylindrical battery is obtained, the cylindrical battery has a diameter of 46mm and a height of 95mm; its capacity is about 32Ah.

[0081] Comparative Example

[0082] (Preparation of positive electrode sheet)

[0083] The positive electrode active material - LiNi 0.8 Co 0.1 Mn 0.1 O2, conductive carbon black Super-P, and binder PVDF are mixed in a N-methylpyrrolidone (NMP) solvent system in a weight ratio of 97.6:1.3:1.1 by a vacuum mixer to obtain a positive electrode slurry; the positive electrode slurry is continuously coated on two opposite surfaces of a 12 μm Al foil substrate; and then dried, cold pressed, slit, and cut to obtain a positive electrode sheet.

[0084] (Preparation of negative electrode sheet)

[0085] The negative electrode active material - graphite, the conductive agent sp (also known as Super-P), the binder - styrene-butadiene rubber and the thickener - sodium carboxymethyl cellulose are dissolved in deionized water in a weight ratio of 96.5:1:1.2:1.3, and the negative electrode slurry is obtained after being fully stirred and mixed.

[0086] The negative electrode slurry is coated on two opposite surfaces of the negative electrode current collector 6 μm Cu foil by an extrusion coater, and the body is dried, cold pressed and cut in sequence to obtain the negative electrode sheet of this comparative example.

[0087] (Preparation of Electrolyte)

[0088] Ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) are mixed in a volume ratio of 3:3:4 to obtain an organic solvent, and then fully dried LiPF6 is dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0089] (Preparation of isolation film)

[0090] The isolation membrane substrate is 8 μm thick polyethylene (PE), and a 2 μm alumina ceramic layer is coated on both opposite sides of the isolation membrane substrate. Finally, 2.5 mg of binder polyvinylidene fluoride (PVDF) is coated on both sides of the ceramic layer and dried.

[0091] (Preparation of cylindrical batteries)

[0092] The positive electrode sheet, isolation film and negative electrode sheet of this comparative example are stacked in order, so that the isolation film is placed between the positive electrode sheet and the negative electrode sheet to play an isolating role, and then wound to obtain a bare battery cell; the qualified bare battery cell is loaded into a cylindrical shell, and then the tabs are welded to the top cover current collecting plate, and finally the electrolyte of this comparative example is injected after drying, and after standing, forming, aging, sealing nail welding and other processes, a lithium-ion cylindrical battery is obtained, the cylindrical battery has a diameter of 46mm and a height of 95mm; its capacity is about 32Ah.

[0093] After testing, the electrolyte injection amount of the embodiment is 65g, and the electrolyte injection amount of the comparative example is 58g; and the gas production discharged during formation and high-temperature standing for 24 hours after formation is monitored. The gas exhaust volume of the embodiment is 36g, and the gas exhaust volume of the comparative example is 29g; the capacity of the cylindrical battery of the embodiment after 1000 cycles is 28.9Ah, and the capacity of the cylindrical battery of the comparative example after 1000 cycles is 26.7Ahg. It can be seen that the cylindrical positive electrode plate of the embodiment of the present application is significantly improved in terms of gas exhaust volume and cycle performance compared with the positive electrode plate of the comparative example, and the safety is higher.

[0094] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0095] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0096] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0097] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0098] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0099] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A positive electrode sheet for a cylindrical battery, characterized in that: include: current collector; A first positive electrode material layer, wherein the first positive electrode material layer is provided on at least a portion of at least one surface of the current collector; The second positive electrode material layer is arranged on at least a portion of the surface of the first positive electrode material layer away from the current collector; the second positive electrode material layer includes a plurality of coating areas, and a gap blank area is provided between two adjacent coating areas.

2. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: A plurality of coating zones are arranged in parallel.

3. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: The widths of the plurality of gap blank areas are equal.

4. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: The widths of the plurality of gap blank areas are not equal.

5. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: The width of the gap blank area is 0.5-10mm.

6. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: The positive electrode active material of the first positive electrode material layer is different from the positive electrode active material of the coating area; And / or, a surface of the coating region away from the current collector is arranged in parallel with the current collector.

7. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: The positive electrode active material of the first positive electrode material layer is LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2、LiNi 0.5 Co 0.2 Mn 0.3 O2、LiNi 0.6 Co 0.2 Mn 0.2 O2、LiNi 0.8 Co 0.1 Mn 0.1 O2、LiNi 0.9 Co 0.05 Mn 0.05 O2, lithium iron phosphate or lithium iron manganese phosphate; And / or, the positive electrode active material in the coating area is lithium iron phosphate or lithium manganese iron phosphate.

8. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: The thickness of the first positive electrode material layer is 40-120 μm.

9. The positive electrode sheet of a cylindrical battery according to claim 1, characterized in that: The coating area has a thickness of 2-30 μm.

10. A cylindrical battery, characterized in that: A positive electrode sheet comprising a cylindrical battery as claimed in any one of claims 1 to 9.

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